Comment by pjc50
6 hours ago
Yes, cycle-accurate is very expensive because it prevents optimization. But as described they say they're doing an AOT version of cycle-accurate anyway?
In some ways this is similar to the concurrent-systems problems that memory barriers are a tool to address. Your emulator will come in two halves, a CPU side and a gfx/sfx side, as well as control inputs, and the "intermediate" approach is when you're just trying to preserve the sequence of load/stores between the two with an accuracy relative to frame timing. Maintaining ultra precise timing within a frame imposes more detailed coordination requirements on both sides of the emulation.
Being cycle-accurate is annoying when you want full realtime if the hosting platform doesn't have enough CPU power to emulate all parts at full speed.
I guess the point is that a pre-compiled version could have HW checkpoints from a slow emulated run, so that it can then run at full speed and just advance the HW to the required timestate when a write is to occur (ie, instead of costly cycle-accurate emulationg, most HW operations can be batched inbetween time-sensitive checkpoints).
Then again, why not just record a video at that point? :P